10220821 has 8 divisors (see below), whose sum is σ = 11109560. Its totient is φ = 9346752.

The previous prime is 10220807. The next prime is 10220827. The reversal of 10220821 is 12802201.

It can be written as a sum of positive squares in 4 ways, for example, as 2160900 + 8059921 = 1470^2 + 2839^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 10220821 - 2²³ = 1832213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10220795 and 10220804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10220827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2190 + ... + 5023.

It is an arithmetic number, because the mean of its divisors is an integer number (1388695).

Almost surely, 2^10220821 is an apocalyptic number.

It is an amenable number.

10220821 is a deficient number, since it is larger than the sum of its proper divisors (888739).

10220821 is a wasteful number, since it uses less digits than its factorization.

10220821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7335.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 10220821 is about 3197.0018767589. The cubic root of 10220821 is about 217.0177521632.

The spelling of 10220821 in words is "ten million, two hundred twenty thousand, eight hundred twenty-one".